A letter which I have just received from India from Dr. Joseph Hooker, who is engaged in meteorological and geological researches, as well as those connected with the geography of plants, says: “Mr. Hodgson, who we regard here as the geographer best acquainted with the hypsometric relations of the snow ranges, completely recognises the correctness of your statement in the third part of the Asie Centrale, respecting the reason of the inequality in the height of the limit of perpetual snow on the northern and southern declivities of the Himalaya. In the ‘trans Sutlej region’ in 36° lat. we often saw the snow limit only commence at an altitude of 20000 English feet, while in the passes south of the Brahmaputra, between Assam and Burman, in 27° lat., where the most southern Asiatic snowy mountains are situated, the limit of perpetual snow sinks to 15000 English feet.” I believe we ought to distinguish between the extreme and the mean heights, but in both we see manifested in the clearest manner the formerly contested differences between the Thibetian and the Indian declivities. My statements respecting the mean | Extremes according to Dr. height of the Snow-line | Joseph Hooker’s letter. in the Himalaya. | (Asie Centrale, tom. iii. p. 326.) | Paris Eng. | Paris Eng. feet. feet. | feet. feet. Northern declivity 15600 16626 |Northern declivity 18764 20000 Southern „ 12180 12981 |Southern „ 14073 15000 ----- ----- | ----- ----- Difference 3420 3645 | Difference 4691 5000 The local differences vary still more, as may be seen from the list of extremes given in my Asie Centrale, T. iii. p. 295. Alexander Gerard saw the snow limit ascend, on the Thibetian declivity of the Himalaya, to 19200 Parisian feet (20465 English); and on the southern Indian declivity, Jacquemont once saw it, north of Cursali on the Jumnotri, even as low as 10800 Parisian (11,510 English) feet. [11] p. 6.--“_A brown Pastoral Race, the Hiongnu._”